This invention relates to a position transducer for detecting position in three generally orthogonal directions.
In accordance with the invention there is provided a base unit, a mobile unit movable relative to the base unit, a generally tubular elongate guide arm fixed to the base unit and arranged to be angularly movable such that it in use, it extends generally towards the mobile unit, and a variable length coupling line passing through the guide arm and fixed to the mobile unit at its distal end, the transducer being operable to output information about the angular position of the guide arm and the extended length of the coupling line from which information, the relative positions of the base unit and mobile unit are calculable.